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In the framework of its R&T activities, French Space Agency CNES has entrusted the study of the
consequences of high velocity impact on a composite overwrapped pressurized vessels to two SMEs THIOT
INGENIERIE and IMPETUS AFEA. The general context of this project is to study the vulnerability of a
pressurized tank onboard spacecraft impacted by a projectile at high velocity. Tanks selected for this study
are commercially available that consist of an aluminum liner and four composite layers made of carbon
fibers and silica fibers. The impact tests, performed by THIOT INGENIERIE, were instrumented with
suitable metrology in the field of shock to identify the main physical phenomena associated to the
hypervelocity impact of a few grams aluminum ball on a pressurized tank. Numerical simulations of these
impact configurations were performed with IMPETUS AFEA solver which is based on innovative and
advanced numerical methods: High order Finite Elements, meshless method called gSPH. This unique
approach has been fully implemented in 3 dimensions and represents the real geometry of the tanks (as
opposed to 2D axisymmetric simulations). Performing comparison with experiment, numerical simulation
reproduces the main physical phenomena identified in the experiments, as the 3D cracking failure modes.
Although some items would need to be improved to better reproduce the physical mechanisms, the
reliability of these calculations is sufficient to extrapolate these first results in a range of more
representative impact operational applications (impact velocity > 15 km / s). Thus a method for analyzing
such impact configurations is set to address the risk of tank loss or explosion and space debris generation.
The proposed method to answer this question is to implement in a coordinated way, tests of impact on
tanks, load calculations and material behavior characterization in the ranges encountered in these extreme
impacts configurations.
